All of these would require huge amount of new lore to justify them. Also, High Elf is physically the same as BE so I don't know what's the point. Just coppy BE's model for AA?

no they wouldnt all those sub races are already allied or have factions allied with the respective faction with the exception of felblood elves and wretched (maybe forest trolls depending on whether blizzard still counts the revantusk tribe)

the majority of the work comes with either developing a new model or making armor work on the current models they have.

some require less work than others but if they decide to do subraces its not like they have to do them all at once and they can have them be unlocked in different ways.

"I was a normal baby for 30 seconds, then ninjas stole my mamma" - Deadpool
"so what do we do?" "well jack, you stand there and say 'gee rocket raccoon I'm so glad you brought that Unfeasibly large cannon with you..' and i go like this BRAKKA BRAKKA BRAKKA" - Rocket Raccoon

no they wouldnt all those sub races are already allied or have factions allied with the respective faction with the exception of felblood elves and wretched (maybe forest trolls depending on whether blizzard still counts the revantusk tribe)

the majority of the work comes with either developing a new model or making armor work on the current models they have.

some require less work than others but if they decide to do subraces its not like they have to do them all at once and they can have them be unlocked in different ways.

I don't see why they couldn't offer alternate textures though, they wouldn't be any different than the undead-skins that Death Knights get, albeit with a little more lore attached to them.
Textures don't require Blizz to remodel armor and animations like some of the sub-race suggestions out there.

The original idea behind the majority of subraces was variant skins, not new models. Overtime we've built up a lot of custom NPC races now though with new models, so yes, people have actual different models in mind now, but still, every single one of your photoshop examples should be there too I think, I'd request a Fel Orc from you, that would kick ass Those examples totally rock btw.
But if I was a fel orc I'd just want red skin, not the bone growths. The fel orcs we've seen in the Horde seem to have lost the spikes, and I prefer a simple red option. Like this fellow from the Pearl of Pandaria.

But when it comes to the sub races being distinct and unique models, I don't think the majority of the custom models in game beyond the last two expansions have the quality expected for a player model, especially in facial expressions and animations, they would need to be completely redone. It's a lot more realistic I think to expect skin variants of the updated models with new expanded customization like Chris Robinson is talking about a lot on his twitter page for the project concerning new hairstyles and beards and things not borrowed from other races to use on a different race like the last hairstyle update we got but completely new concepts and styles modeled to evoke the art of the Sons of the Storm more. I think just giving us the current NPC Taunka or Yaungol would be a mistake and a rush job compared to the new player models we're getting.

Lore based tattoos for many of the races would rock. Just for those who still don't know, we did get Wildhammer tattoos for dwarf players early in Cata's beta. It was just the option to use the new Twilight Highland NPC skins so your customization was severely limited, but it kicked so much ass to have a blue bar across my dwarf's eyes. It was removed within a few weeks of the beta's beginning though.

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Originally Posted by Narna

This is actually pretty cool. I think that this is very do-able by Blizzard, but I'm guessing they won't.

Well they've already said last year and this year at Blizzcon it's something they want to do. They are right now working and brainstorming on a lot of brand new concepts for customization as we speak according to the art director's twitter feed. From hairstyles and racial armor and weapons to orcs who stand up straighter.

didn't know about that wildhammer tattoo Yig, why the hell would they remove something they'd gone to the trouble to implement? surely it harms absolutely nobody to leave something like that in, infact, going to the trouble to remove it just seems weird.

no they wouldnt all those sub races are already allied or have factions allied with the respective faction with the exception of felblood elves and wretched (maybe forest trolls depending on whether blizzard still counts the revantusk tribe)

the majority of the work comes with either developing a new model or making armor work on the current models they have.

some require less work than others but if they decide to do subraces its not like they have to do them all at once and they can have them be unlocked in different ways.

NE has cut all ties with dark troll and don't even know they are related to them at all.

Furbog and pandaren have almost nothing to do with each other except that pandaren seems to have evolved from them.

NE worgen would start in Teldrassil? also. lore wise they could only be druid right? because NE worgens were all druid of the pack.

didn't know about that wildhammer tattoo Yig, why the hell would they remove something they'd gone to the trouble to implement? surely it harms absolutely nobody to leave something like that in, infact, going to the trouble to remove it just seems weird.

My guess was because it was so limited. You could choose your tattoo, but it was bound to only one skin palor, and I think your actual face was bound as well. Pretty much you could only change hairstyles after choosing your tattoo, while being forced to use the preset skin. I think it was a dev doing something they thought was cool and possibly worth expanding on later, but they shelved it due to not wanting to half ass it and not having room on the immediate schedule, knowing they'd probably be working on new player models in the next year or two.